Abstract
BACKGROUND: This study evaluates the effectiveness of 0.3% hyaluronic acid (HA) eye drops in patients receiving concurrent botulinum toxin (BoNT) injections for benign essential blepharospasm (BEB) or hemifacial spasm (HFS). METHODS: This randomized controlled cross-over trial study involved 14 patients with BEB and 33 patients with HFS randomized into two groups (early treatment and deferred treatment) for 3 months of treatment with 0.3% HA eye drops. Data collected at baseline, 3 months, and 6 months included Blepharospasm Severity Scale (BSS) score in patients with BEB; Samsung Medical Class Grading Scale score in patients with HFS; and dry eye symptoms, lower eyelid tear meniscus height (TMH), tear breakup time (TBUT), and corneal fluorescein staining in both groups. RESULTS: After 3 months of 0.3% HA instillation, patients with BEB in both groups showed significant improvement in BSS, TMH, TBUT, and the amelioration of subjective dry eye symptoms and corneal staining (P < 0.05). However, discontinuation of 0.3% HA eye drops worsened BSS, TMH, and TBUT. Patients with HFS also experienced significant improvement in Samsung Medical Class score, subjective dry eye symptoms, and objective corneal findings (P < 0.05). CONCLUSIONS: Treatment with 0.3% HA eye drops led to significant improvement in spasm severity, and dry eye parameters, after 3 months of instillation in patients with BEB or HFS during concurrent treatment with BoNT injections. The 0.3% HA eye drops were safe and might serve as an add-on treatment for symptom improvement.